Objective-C Programming For Dummies
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In programming, as in life, you have to make decisions and act on them. Objective-C provides control statements and loops to help your program take action. You may want to repeat a set of instructions based on some condition or state, for example, or even change the program execution sequence. Here is the basic syntax for Objective-C control statements and loops.

if else

<b>if</b> (condition) {
  statement(s) if the condition is true;
<b>else</b> {
  statement(s) if the condition is not true;


<b>for</b> (counter; condition; update counter) {
  statement(s) to execute while the condition is true;

for in

<b>for</b> (Type newVariable <b>in</b> expression ) {
<b> </b> statement(s); 
Type existingVariable ;
for (existingVariable in expression) {
  • *Expression is an object that conforms to the NSFastEnumeration protocol.

  • An NSArray and NSSet enumeration is over content.

  • An NSDictionary enumeration is over keys.

  • An NSManagedObjectModel enumeration is over entities.


while (condition) { 
  statement(s) to execute while the condition is true 

do while

do {
  statement(s) to execute while the condition is true 
  } while (condition);

Jump statements

return ;

Stop execution and return to the calling function.


Leave a loop.


Skip the rest of the loop and start the next iteration.

goto labelName;

An absolute jump to another point in the program (don't use it).


Terminates your program with an exit code.

About This Article

This article is from the book:

About the book author:

Neal Goldstein is a veteran programmer and trusted instructor of iOS programming topics. He is the author of all editions of iPhone Application Development For Dummies. Karl Kowalski is a programmer who specializes in security and mobile apps and author of Mac Application Development For Dummies.

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